Factors associated with non-initiation of latent tuberculosis treatment among healthcare workers with a positive interferon-gamma releasing assay

Despite widespread use of the interferon-gamma release assay for the diagnosis of latent tuberculosis infection (LTBI), the initiation rate of and factors associated with LTBI treatment among healthcare workers (HCWs) have not been studied in depth. The aim of this study was to evaluate the initiation rate of LTBI treatment and also to identify any factors associated with non-initiation of LTBI treatment among HCWs. A retrospective cohort study of 293 HCWs with LTBI was performed at a teaching hospital in Korea. LTBI was diagnosed using QuantiFERON-TB Gold In-Tube tests (Cellestis Ltd., Carnegie, VIC, Australia). Of the 293 HCWs with LTBI, 189 HCWs (64.5%) visited an outpatient clinic for a medical consultation regarding LTBI treatment. Of these, 128 (67.7%) consented to LTBI treatment for a 43.7% LTBI treatment initiation rate. Upon multivariable analysis, having a liver disease or currently taking hepatotoxic drugs (adjusted odds ratio [OR] = 12.03, 95% confidence interval [CI] = 3.12-46.35), being a physician (adjusted OR = 14.01, 95%Cl = 2.82-69.74) and other patient-related HCWs (adjusted OR = 3.58, 95%Cl = 1.46-8.78), and years of employment >= 20 years (adjusted OR = 4.77, 95% CI = 1.74-13.12) were independent factors associated with the non-initiation of LTBI treatment. Upon bivariate multivariable analysis, while having a liver disease or currently taking hepatotoxic drugs (adjusted OR = 12.85, 95% CI = 3.06-55.92), being a physician (adjusted OR = 28.43, 95% CI = 4.78-169.28) and other patient-related HCWs (adjusted OR = 4.80, 95%Cl = 1.56-14.74), and years of employment >= 20 years (adjusted OR = 4.55, 95%Cl = 1.37-15.15) were factors associated with no outpatient clinic visit for a consultation of LTBI treatment, having a liver disease or currently taking hepatotoxic drugs (adjusted OR = 11.76, 95% CI = 2.68-51.73) and years of employment >= 20 years (adjusted OR = 5.29, 95%Cl = 1.38-20.19) were factors associated with refusal of LTBI treatment after a consultation. The overall initiation rate of LTBI treatment was suboptimal in HCWs with LTBI diagnosed using an interferon-gamma releasing assay. Having a liver disease or currently taking hepatotoxic drugs, being a physician and other patient-related HCWs, and years of employment >= 20 years were associated with non-initiation of LTBI treatment.